Console redirection among linked computers

ABSTRACT

A technique for providing communication between two computers through a network in a way to allow one computer to control the other.

[0001] This application is a continuation (and claims the benefit ofpriority under 35 USC 120) of U.S. application Ser. No. 09/387,614,filed Aug. 31, 1999. The disclosure of the prior application isconsidered part of (and is incorporated by reference in) the disclosureof this application.

BACKGROUND

[0002] This disclosure generally relates to communication among linkedcomputers, and more specifically, to access and control of one computerby a remote computer.

[0003] Computers, their peripherals, and other information processingdevices can be connected to one another by communication channels toform computer networks. The communication channels may be wired linkssuch as electrical cables and optic fibers, or wireless links by radiowaves, or a combination of both. Linked computers can communicate withone another to exchange data and share various hardware and softwareresources over the network.

[0004] A computer connects to a network by using a network interfacecard (“NIC”). Other information processing devices may also use a NIC tocommunicate with a network. The NIC essentially operates as an agent toprovide communication between the computer and the network. Each NIC canhave a hardwired identification number known as medium access control(“MAC”) address so that an associated computer can be uniquelyidentified by other computers in the network.

[0005] Computers in a network, e.g., a local network (“LAN”), may havedifferent properties from one another, such as hardware configurations,NIC specifications, and operating systems. Communication protocols canencode the data in a way that different computers can “understand” oneanother regardless their differences. In addition, different networkswithin a wide area network (“WAN”) may use different protocols. Hence,additional protocols may be used to allow communication betweendifferent networks. For example, the Internet uses TCP/IP protocols asits WAN communication protocols and a computer is assigned with anInternet protocol (IP) address in order to be uniquely identified andrecognized over the Internet.

[0006] One trend in network computing is to increase the accessibility,manageability, and control of hardware, software, or data in the networkby a user from a different location where a link to the network isavailable. For example, a networked computer may implementinstrumentation to allow remote access of its internal system contents(e.g., hardware and software components, static and dynamic data in itsmemory units) from an authorized computer via the network. As anotherexample, a computer may be booted by first downloading system softwarefrom a remote server across a network and then executing the bootroutine. This preboot operation can be implemented by using the PrebootExecution Environment (PXE) technology (Wired For Management 2.0, Intel,1998).

SUMMARY

[0007] The present specification provides a technique for exchangingdata between two networked computers to allow one computer to controlthe other and to share the hardware and software resources. Oneembodiment of the technique uses a basic input and output system (BIOS)of a first computer to control a network interface card (NIC) tocommunicate with a second computer in a network. A timer interrupt isgenerated based on a timing signal in the first computer. The BIOS ofthe first computer is configured to communicate with the second computeraccording to the timer interrupt to allow the second computer to controlthe first computer both when the first computer has a running operatingsystem, and when the first computer does not have a running operatingsystem.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 shows one embodiment of a computer that implements aconsole redirection to a remote computer.

[0009]FIG. 2 is a flowchart of one embodiment of console redirection.

[0010]FIG. 3 is a flowchart for one implementation of consoleredirection based on the Preboot Execution Environment technology.

DETAILED DESCRIPTION

[0011]FIG. 1 shows one computer 100 that is connected to a network 120to communicate with a remote computer 130. The techniques disclosedherein are operable to configure and control the computer 100 so thatoperations of the computer 100 can be controlled from another remotecomputer (e.g., the computer 130) as if the user were physicallypresent. This allows sharing of hardware and software resources betweenthe computers 100 and 130. The above operation appears to “redirect” thecontrol console of the computer 100 to a remote computer 130. The remotecomputer 130 may be at any location that has a link to the network 120and may be a portable computer, a desktop PC, a workstation, or anyother information processing device based on a computer processor. Thisconsole redirection improves the efficiency and reduces costs inresource sharing, service, and management of networked computers.

[0012] In one embodiment, the computer 100 includes a processor 102(e.g., an Intel microprocessor), a system bus 104, and a NIC 116connected to the system bus 104. The system bus 104 also connects othercomputer devices within the computer 100, among which only I/O devices106 (e.g., keyboard and monitor), a read-only memory (“ROM”) 108, arandom-access memory (“RAM”) 110, an interrupt controller 112, and atimer logic circuit 114 are shown as examples. A basic input and outputsystem (“BIOS”), i.e., a set of operating routines or instructions thatcontrol data communication between different devices within a computer,is stored in the ROM 108. When the computer 100 is turned on, the BIOSinstructions are executed by the computer processor 102 to initializeand establish communication of the devices connected to the system bus104 (including the NIC 116). Then, an operating system is launched tocontrol the operations of the computer 100. The operating system may beinstalled locally within the computer 100 or in a remote deviceconnected to the network 120.

[0013] At least a portion of the RAM 110 is allocated to buffer datareceived through the NIC 116 from the network 120 and data generated byother devices in the computer 100 that is to be sent to the network 120.A data packet from the network 120 is first stored in the RAM 110 andthen the BIOS unpacketizes the data and sends it to a respective device.Similarly, the outgoing data is first captured and stored in the RAM 110and is then transmitted to the network 120 in a packet form based on aprotocol used by the BIOS.

[0014] The NIC 116 may include a network controller, NIC memory units, asystem interface to the computer system bus 104, and a communicationport that connects to the network 120 through at least one communicationchannel. The network controller is a logic circuit that controls the NICoperations including communication between the NIC 116 and the BIOS ofthe computer through the system interface and communication between theNIC 116 and the network 120 through the communication port. The NICmemory units may include a RAM and a ROM. The RAM may function as amemory buffer to temporarily store data that either is sent to orreceived from the network 120. The ROM, which may be implemented by anelectronically erasable programmable ROM (“EEPROM”), may store NICapplication programs such as communication programs to control thenetwork controller and the NIC operations. Although only one NIC 116 isshown, the computer 100 may include two or more NICs.

[0015] The network 120 uses a given set of communication protocols tocontrol and organize the communication among different computers. A partof the BIOS in the ROM 108 of the computer 100 implements theseprotocols to translate or interpret data generated by the computer 100in a way that is independent of its computer hardware and softwareconfigurations. Hence, the computer 100 and other computers “speak” thesame language at the network level, i.e., they use a common data formatfor data packets that are exchanged through the network 120.

[0016] Another function of the protocols is network addressing. When thecomputer 100 is connected to the network 120 through its NIC 116, arouter, i.e., a computer connected in the network 120 to control thenetwork communication, assigns a network address to the computer 100(e.g., the IP address in the TCP/IP). The data sent out by the computer100 is packaged with the assigned network address and other informationin the packet header according to the given protocols. Hence, anycomputer in the network 120 (e.g., the remote computer 130) canrecognize that the data is from the computer 100. Conversely, anothercomputer, when sending data specifically to the computer 100, also addsthe network address of the computer 100 to its data packet header so thenetwork 120 can properly route the data to the computer 100.

[0017] The computer 100 is controlled so that the remote computer 130can access and execute its BIOS in the ROM 108 through the NIC 116 andthe network 120 regardless of the operating status of the computer 100.This access can include, e.g., before or after the computer 100 isbooted, when it experiences a failure, or it is under a power managementmode such as hibernation. In particular, the present console redirectionallows communication between the computer 100 and the remote computer130 when the computer 100 does not have a locally-running operatingsystem (“OS”), e.g., before the OS is launched, when the computer 100has failed to boot for some reason or does not have an OS installedlocally. Hence, the console redirection may be implemented by operationsof software and hardware components at the BIOS level of the computer100 in order to perform certain operations in absence of a local OS andto operate by running an OS in the remote computer 130.

[0018] This OS-independent console redirection may be implemented fromat least two different aspects. First, the BIOS stored in the ROM 108includes special routines and instructions that control and coordinatethe console redirection from the computer 100 to the remote computer130. These special BIOS routines and instructions control operations ofthe NIC 116 and direct data for the console redirection to a desireddestination. For example, the incoming data from the NIC 116 may bedirected by the BIOS to respective devices in the computer 100 forfurther processing or executing certain actions such as the processor102, the I/O devices 106, etc. In addition, these special BIOS routinesand instructions packetize data generated by the computer 100 and sendthe data packets to the NIC 116 for transmission to the network 120based on the communication protocols.

[0019] In another aspect, an NIC hardware layer interface may beimplemented to make the communication between the computer 100 and thenetwork 120 (to the remote computer 130) independent of the specifichardware configuration of the NIC 116. This is desirable because thedifferent NICs may have different hardware configurations due todifferent standards used by different NIC manufacturers and thereforecommunication with different NICs is in general configuration-specific,specially during the communication between the computer 100 and thenetwork 130 prior to boot of the computer 100. This NIC interfacesimplifies the console redirection by minimizing or removing thedependence on the NIC configuration. It can make different NICscommunicate to the network 120 in a uniform manner. Both hardware andsoftware implementations or a combination of both may be used.

[0020] In a software implementation, the NIC interface is an applicationprogramming interface (“API”) having a set of NIC routines. These NICroutines include initialization routines to obtain information on thehardware configuration of the NIC 116, including its MAC address anddata structure, and then convert the obtained NIC information into aformat based on a standard protocol. The converted NIC information istransferred to the RAM 110 to be used by the BIOS in the ROM 108 forcommunicating with the network 120. The NIC routines also establish acommunication link between the NIC 116 and the network 120 for receivingor transmitting data based on the standard protocol under control of theBIOS.

[0021] At least two different types of interrupt service routines(“ISRs”) are involved in the present console redirection. The first typeof interrupts is a timer interrupt service routine. The interruptcontroller 112 periodically generates this timer ISR at periodic timerticks of a clock signal produced by the timer logic circuit 114. TheBIOS in the ROM 108 can execute an operation for the console redirectiononly at a timer ISR. Hence, the frequency of this clock signal partiallydetermines the speed at which the data is sent or received through theNIC 116 by the computer 100. In operation, if there is received datafrom the network 120 or data to be sent out to the network 120, the BIOSdirects the received data to a respective device within the computer 100or sends the data to the NIC 116 for transmission to the network 120 ata timer tick. For example, the interrupt controller 112 can indicate atimer interrupt to the processor 102 which looks at a timer interruptaddress to execute a program. When there is no new data received or tobe sent at a timer tick, the BIOS exits the timer ISR and performs othertasks.

[0022] A second type of interrupt is an asynchronous interrupt generatedby the interrupt controller 112 whenever the NIC 116 receives a datapacket from the network 120. The NIC 116 sends the received data packetto the RAM 110 and the interrupt controller 112 directs the BIOS toprocess the received data as a timer ISR. Such interrupts areasynchronous because data packets from the network 120 arrive atunexpected times depending on the network conditions such ascommunication traffic.

[0023] The BIOS of the computer 100 may control the timer logic circuit114 to adjust the frequency of the clock signal from which the timerinterrupt is generated according to the data flow rate between thecomputer 100 and the network 120. This mechanism allows the computer 100to handle the communication with the remote computer 130 moreefficiently, by dynamically allocating sufficient amount of computingpower of the computer 100 to the communication with the network 120.Ideally, the frequency of the clock signal matches the data flow ratebetween the computer 100 and the network 120. At each and every timertick, a timer interrupt command the BIOS to either send or receive adata packet, and little or no data is buffered in the RAM 110. In anactual implementation, the frequency of the clock signal should matchthe data flow rate as close as possible.

[0024] A set of BIOS routines may be implemented to increase thefrequency of the clock signal as the data flow rate increases and toreduce the frequency of the clock signal as the data flow ratedecreases. One or more monitoring routines may be included in the BIOSto monitor the flow rate. For example, the BIOS may include routines tomonitor the flow rate of data into the allocated area in the RAM 110 forbuffering the communication data, or count the rate of asynchronousinterrupts generated by the NIC 116. The information on the flow rate isthen used to adjust the frequency of the timer ticks.

[0025] In general, any data that is available to the BIOS can be madeaccessible for the remote computer 130, including data packets for thedisplay from the video memory on the status of the system or a device,security information, I/O information, and handshaking information ofthe computer 100. The remote computer 130 can remotely control thecomputer 100 by sending data and commands via the network 120 and theBIOS of the computer 100 would process these data and commands as ifthey were generated locally. The data and commands may include thekeyboard data (e.g., a keystroke or a combination of keystrokes), datafrom a pointing device (e.g., the mouse), and instructions generated byone or more application programs running on the remote computer 130. Inthis context, the console of the computer 100 is redirected to theremote computer 130. In addition, this console redirection allows anoperation in the computer 100 to use hardware or software resourcesresiding in the remote computer 130 or vice versa.

[0026] The above console redirection is achieved at least in part byconfiguring and operating the NIC 116 to send desired data from the BIOSof the computer 100 to the remote computer 130 and to receive data fromthe remote computer 130, all through operations of the BIOS of thecomputer 100. The BIOS of the computer 100 has routines for capturingand packetizing the data in the computer 100 with headings according tocommunication protocols so that the data can be routed to the remotecomputer 130 through the network 120. In addition, the BIOS has routinesfor unpacketizing received data packets by the NIC 116 and directing thedata to respective devices in the computer 100.

[0027]FIG. 2 shows a flowchart 200 that illustrates one embodiment ofthe console redirection. Steps 210 and 230 are initializing steps whenthe power to the NIC 116 is first turned on to obtain the information onthe hardware configuration of the NIC 116 and to prepare the NIC 116 forcommunication with the network 120. At step 210, the parameters of NIC116 and its MAC address are obtained and stored in the RAM 108 of thehost computer 100. This may be done by using the NIC routines in the NICROM. Then the NIC 116 is connected to the interrupt controller 112 forexecuting the asynchronous ISR triggered by receiving of a data packetfrom the network 120 (step 220). Next, the communication between the NIC116 and the network 120 is established by first requesting and obtaininga network address for the computer 100 from a server (step 230).

[0028] Computers 100 and 130 need to know each other's network addresses(e.g., IP addresses) in order to communicate. The address of the remotecomputer 130 may be stored in the ROM 108 in advance or communicated tothe computer 100. The BIOS in the computer 100 may include the routinesto inform the remote computer 130 of the network address for thecomputer 100 upon completion of the step 230. For example, the BIOS ofthe computer 100 may include an electronic mail routine (e.g., theSimple Mail Transfer Protocol for the Internet) to send thenewly-assigned network address via email to the remote computer 130.

[0029] At step 240, a timer interrupt is issued at a timer tick when theBIOS controls the NIC 116 to send data to or receive data from theremote computer 130. The BIOS packetizes the data to send the first datapacket to the remote computer 130. After sending the first data packet,the BIOS controls the NIC 116 to wait for an acknowledgment from theremote computer 130 for receiving a previous data packet sent by thecomputer 100 (step 250). When the acknowledgment is received by the NIC116, the BIOS then determines whether a data packet intended for thecomputer 100 is received from the network 120. If no data is received,the BIOS opens a network link between the NIC 116 and the network 120 ata timer tick to packetize data from the BIOS and sends the data packetaccording to an accepted communication protocol, i.e., a timer ISR isexecuted (step 280). If data packet for the computer 100 is received,the BIOS first unpacketizes the received data packet at a timer tick andsends the respective data to intended devices in the computer 100 (step290). The operation to send data to the network 120 is then executed ina later timer ISR.

[0030] The remote computer 130 may generate an acknowledgment signaleach time it receives a data packet from the computer 100.Alternatively, the remote computer 130 may generate an acknowledgmentsignal after receiving two or more data packets from the computer 100.This latter method may be used to increase the speed and throughput ofthe communication between the computers 100 and 130. In particular, theremote computer 130 may adjust its frequency of acknowledgement based onthe network conditions (e.g., data traffic). When the delay betweencomputers 100 and 130 is relatively short, the computer 130 can send anacknowledgement signal to the computer 100 upon receiving one datapacket therefrom. The computer 130 may reduce its frequency ofacknowledgement when the delay increases, e.g., sending oneacknowledgement signal to the computer 100 after every two or more datapackets are received. The sliding window protocol is one example of suchan adjustable acknowledgement mechanism.

[0031] If the acknowledgment for receiving a previously-sent data ispending (i.e., not received), the NIC 116 exits the timer ISR and waitsto act upon the next timer interrupt. The NIC 116 resumes the timer ISRto execute steps 270, 280, or 290 to send data at a timer tick wheneverthe acknowledgment is received. In one aspect, the above BIOS routine ofthe computer 100 ensures that the computer 130 has the most currentstatus of the computer 100 by executing any new command from the remotecomputer 130 or sending out any data only after the acknowledgment isreceived.

[0032] The remote computer 130 also uses the aboveacknowledgment-and-sending sequence to send data and commands to thecomputer 100. For example, the remote computer 130 receives console datasuch as display data from the computer 100 that indicates the currentoperating state. To control the computer 100 to perform a task, theremote computer 130 sends out data which may include a keystroke, acommand, or a cursor action of a pointing device in the remote computer130. The NIC 116 of the computer 100 receives and copies the data to theRAM 110. At a timer tick when a timer ISR is generated, the BIOS decodesthe received data to determine its intended device in the computer 100(e.g., processor 102 or a peripheral). The intended device then executesthe command. The execution result is captured and stored in the bufferof the NIC 116 and the routine shown in FIG. 2 is performed to send theresult to the remote computer 130. The remote computer 130 may then sendanother command to control the computer 100.

[0033] One implementation of the above console redirection technique ofFIG. 2 uses instructions associated with the physical layer of thePreboot Execution Environment (“PXE”) protocols. PXE instructions arestored in the NIC ROM as firmware to download an executable program froma server and to run the program locally in the client machine such asinstalling an operating system, booting the client, or the changing theconfigurations of the client. The PXE resides in the NIC ROM andincludes a set of Universal Network Device Interface (“UNDI”)instructions as the physical layer of network communication. Thisembodiment of console redirection uses this part of PXE as a physicallayer driver for the NIC 116 to send data to the network 120 accordingto the User Datagram Protocol (“UDP”).

[0034]FIG. 3 shows the detailed implementation of console redirectionbased on PXE. At step 310, the PXE UNDI instruction “STARTUP” isexecuted to set up data structure and memory locations inside the BIOSof the computer 100. The UNDI instruction “INITIALIZATION” resets theNIC 116 into its default parameters. Then the UNDI instruction “GETINFORMATION” executes to copy the NIC variables including its MACaddress into the RAM 110.

[0035] At steps 320 and 330, the interrupt controller 112 is linked tothe NIC 116 to handle the asynchronous ISR generated by the NIC 116.This is done by using UNDI instruction “ISR” within the PXE. At step320, the NIC 116 is connected to an available IRQ link to the interruptcontroller 112 based on information of the NIC 116 obtained from “GETINFORMATION”. Then the IRQ pointer is set to the address of the ISRretrieved from the ROM of the NIC 116.

[0036] The above operations prepare the hardware configurations of theNIC 116 for communication with the remote computer 130 through thenetwork 120. Subsequent operations establish a communication linkbetween the computers 100 and 130 and perform data transmission.

[0037] At step 340, the Dynamic Host Configuration Protocol (“DHCP”) isused to get an IP address for the computer 100. First, the BIOS of thecomputer 100 broadcasts a DHCP request for an IP address and IPconfiguration parameters to DHCP servers in the network 120 through theNIC 116. One or more DHCP servers may respond to the request by sendingtheir proposed IP addresses and configurations to the BIOS. The BIOS ofthe computer selects an IP address from a DHCP with desiredconfiguration parameters. At this point, the computer 100 is ready tocommunicate with the remote computer 130.

[0038] Next, the BIOS of the computer 100 initializes a timer interruptat a timer tick for sending data to the remote computer 130. First, theBIOS checks whether an acknowledgment from the remote computer 130 (step350) is pending. If an acknowledgment is still pending at the next timertick, the timer ISR is terminated and no data is sent until theacknowledgment is received (step 360).

[0039] If the acknowledgment from the remote computer 130 is received, atimer ISR is executed as follows. First, the BIOS determines whether isany received data in the RAM 110. If no new data is received, the BIOSpacketizes the outgoing data in its RAM 110 and executes UDP OPEN toopen a UDP connection to the network 120 at the next timer tick. Then,the BIOS uses UDP WRITE to write a data packet to the UDP connectionwhich is sent to its intended receiver 130 over the network 120. Next,the UDP CLOSE is executed to terminate the link (step 380). If there'sreceived data buffered in the RAM 110, BIOS executes UDP OPEN, UDP READ,and UDP CLOSE to retrieve the received data. The BIOS then unpacketizesthe received data and send the data to one or more intended devices forexecution (step 390).

[0040] One application of the above console redirection is to serviceand boot the computer 100 from the remote computer 130. Since data canbe sent from the remote computer 130 to the computer 100, the computer100 may boot by directly using the operating system stored in the remotecomputer 130 without downloading the operating system files. Theexecution routines of the operating system running in the remotecomputer 130 are sent to the computer 100 in form of data packetsthrough the network 120. In another application, a user at the remotecomputer 130 may also use the resources in the computer 100 to runapplications by simply redirecting the console of the computer 100 tothe remote computer 130.

[0041] Furthermore, the console redirection may allow the remotecomputer 130 to performing certain operations in the computer 100 byremotely running one or more applications in the remote computer 130.For example, the remote computer 130 can diagnose software errors in thecomputer 100 and execute commands to fix the errors by running adiagnosis application in the remote computer 130. Alternatively, theremote computer 130 can send certain software components to update theapplication software installed in the computer 100 and hence to correctthe errors.

[0042] Although only a few embodiments have been described, variousmodifications and enhancements may be made without departing from thescope of the following claims.

What is claimed is
 1. A method of controlling operations on a hostcomputer using a control computer, comprising: receiving a plurality ofreceived data packets from the control computer, the received datapackets including information to control the at least one operation ofat least one device on the host computer; transmitting a plurality oftransmitted data packets from the host computer to the control computer,the transmitted data packets including information based on controllingone or more operations of the host computer; and processing the receiveddata packets and the transmitted data packets, wherein the processingincludes: initiating a first timer interrupt; initiating a second timerinterrupt at a time interval after the fist timer interrupt; determiningwhether a data packet has been received from the control computer duringthe time interval; and if a data packet has been received from thecontrol computer during the time interval, unpacketizing the datapacket, sending associated unpacketized data to one or more devices inthe host computer, and controlling at least one operation of the one ormore devices based on the unpacketized data.
 2. The method of claim 1,further including determining a different time interval based on a dataflow rate.
 3. The method of claim 2, wherein the different time intervalis determined to match a timer interrupt rate with the data flow rate.4. The method of claim 1, further comprising packetizing data totransmit to the control computer if a data packet has not been receivedfrom the control computer during the time interval.
 5. The method ofclaim 1, wherein the associated unpacketized data includes executableinstructions for the intended device on the host computer.
 6. The methodof claim 5, further comprising: determining the intended device; andexecuting the executable instructions on the intended device.
 7. Themethod of claim 6, wherein the intended device is chosen from the CPU ofthe host computer and a peripheral of the host computer.
 8. The methodof claim 6, further comprising producing an execution result based onexecuting the executable instructions.
 9. The method of claim 8, furthercomprising packetizing the execution result and transmitting one or morepackets including the execution result to the control computer.
 10. Themethod of claim 1, wherein an operating system is running on the hostcomputer during the controlling.
 11. A method comprising: receiving aplurality of received data packets at network interface of a hostcomputer from a control computer, the data packets including data toremotely control an operation of the host computer; transmitting aplurality of transmitted data packets from the network interface to thecontrol computer, wherein the receiving and transmitting ischaracterized by a data flow rate; processing the received data packetsand the transmitted data packets according to timer interrupts generatedat a timer interrupt frequency, wherein the processing includescontrolling one or more operations of a device on the host computerbased on information in a received data packet; and adjusting the timerinterrupt frequency based on the data flow rate.
 12. The method of claim11, further including monitoring the data flow rate.
 13. The method ofclaim 12, wherein monitoring the data flow rate comprises monitoring theflow rate of data into a memory for buffering received packets.
 14. Themethod of claim 12, further comprising generating an asynchronousinterrupt when a data packet is received from the control computer, andwherein monitoring the data flow rate comprises counting a rate ofasynchronous interrupts.
 15. A host computer, comprising: a networkinterface to receive data packets from a control computer, the datapackets including information to control one or more operations on thehost computer, the network interface further to transmit data packets tothe control computer; an interrupt controller to generate timerinterrupts for processing the received data packets and the transmitteddata packets at a timer interrupt frequency; and a memory including abasic input and output system (BIOS), the BIOS to determine whether adata packet has been received from the control computer during a timeinterval between a first timer interrupt and a second timer interrupt,and if a data packet has been received, the BIOS further to unpacketizethe received data packet.
 16. The computer of claim 15, wherein the BIOSis further to determine an intended device for the received data packet.17. The computer of claim 15, wherein if a data packet was not receivedduring the time interval, the BIOS is to packetize data to transmit tothe control computer.
 18. The computer of claim 15, wherein theinterrupt controller is coupled with timer logic, and wherein the BIOSis further to control the timer logic to adjust the timer interruptfrequency.
 19. The computer of claim 18, wherein the BIOS is to controlthe timer logic to adjust the timer interrupt frequency based on a dataflow rate.
 20. An article comprising a machine-readable medium storinginstructions operable to cause one or more machines to performoperations comprising: receiving a plurality of received data packetsfrom the control computer, the received data packets includinginformation to control the at least one operation of at least one deviceon the host computer; transmitting a plurality of transmitted datapackets from the host computer to the control computer, the transmitteddata packets including information based on controlling one or moreoperations of the host computer; and processing the received datapackets and the transmitted data packets, wherein the processingincludes: initiating a first timer interrupt; initiating a second timerinterrupt at a time interval after the fist timer interrupt; determiningwhether a data packet has been received from the control computer duringthe time interval; and if a data packet has been received from thecontrol computer during the time interval, unpacketizing the datapacket, sending associated unpacketized data to one or more devices inthe host computer, and controlling at least one operation of the one ormore devices based on the unpacketized data.
 21. The article of claim20, wherein the operations further include determining a different timeinterval based on a data flow rate.
 22. The article of claim 21, whereinthe different time interval is determined to match a timer interruptrate with the data flow rate.
 23. The article of clam 20, wherein theoperations further include packetizing data to transmit to the controlcomputer if a data packet has not been received from the controlcomputer during the time interval.
 24. The article of claim 20, whereinthe associated unpacketized data includes executable instructions for anintended device on the host computer.
 25. The article of claim 24,wherein the instructions further include: determining the intendeddevice; and executing the executable instructions on the intendeddevice.
 26. The article of claim 24, wherein the intended device ischosen from the CPU of the host computer and a peripheral of the hostcomputer.
 27. The article of claim 25, wherein the operations furtherinclude producing an execution result based on executing the executableinstructions.
 28. The article of claim 27, further comprisingpacketizing the execution result and transmitting one or more packetsincluding the execution result to the control computer.
 29. The articleof claim 20, wherein an operating system is running on the host computerduring the controlling.